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1. Heat Transfer Coefficient -Air Flow onto perpendicular plane

Hi All, I have a situation were I need to evaluate the heat transfer coefficient of a horizontal surface. The surface has tubes within although I first used "flow across a bank of tubes", this has been untrue due to the air flow coming from above the surface flowing vertically (and...
2. Mechanical principles rotating systems

Homework Statement A shaft 2 m long rotates at 1500 revs min–1 between bearings as shown in FIGURE 2. The bearings experience forces of 5 kN and 3 kN acting in the same plane as shown. A single mass is to be used to balance the shaft, so that the reactions are zero. The mass is to be placed at...
3. Heat exchangers

Homework Statement If the flue gases exiting the boiler are used to preheat the water fed to the boiler from a temperature of 28 C to 90 C and assuming: • a mean specific heat capacity for water over this temperature range to be 4.2 kJ kg–1 K–1 a mean molar heat capacity for the flue...
4. Flame Temperature

C4H10 + 4.5O2 -> 4Co2 + 5H2O1. Homework Statement A fuel gas consists of 75% butane (C4 H10 ), 10% propane (C3 H8 ) and butene (C4 H8 ) by volume. It is to be fed to the combustion chamber in 10% excess air at 25ºwhere it is completely burnt to carbon dioxide and water. The flue gases...
5. Steam produced heat transfer heat exchangers

Homework Statement Dry saturated steam at a temperature of 180oC is to be produced in a fire tube boiler from the cooling of 50 000 kg h–1 of flue gases from a pressurised combustion process. The gases enter the tubes of the boiler at 1600oC and leave at 200oC. The feed water is externally...
6. Butene C4H8

Hi I have tried to search through various books including perrys Can anyone state the net calorific value (lower heating value) for butene C4H8 and the source if possible It would be much appreciated Thanks
7. Counter flow heat exchangers

Homework Statement Process water with a specific heat capacity of 4.182 kJ kg–1 K–1 flows at a rate of 0.050 kg s–1 through a heat exchanger where its temperature is increased from 16°C to 85°C. Heat is supplied by exhaust gases (mean specific heat capacity 1.075 kJ kg–1 K–1) which enter the...
8. Heat transfer and combustion correlations

Hi am a bit stuck on understanding how these two correlations can be similar I am wondering if anyone can ahead any light Can anyone solve Correlation for heat transfer by natural convection from a horizontal pipe to atmosphere is; Nu = 0.53Gr^0.25Pr^0.25 Nu = hd / k Where, Gr =...